Control of fuel valve by carburetor throttle



Feb.A 26, 1957 M, E, JQNES .2,783,034

CONTROL 0F FUEL VALVE: BY CARBURETQR THROTTLE: Filed Feb. 11jl 1954INVEIVTOR. yMALDWYN EJONES ATTORNEY e' se United Staes Pam O CONTRL FFUEL VALVE BY CARBURETOR Y THRTTLE Maldwyn E. Jones, Ferguson, M0.,assigner, by mesne assignments, to ACF Industries, Incorporated, New

York, N. Y., a corporation of New Jersey Application February 11, 1954,Serial No. 409,708

2 Claims.A (Cl. 26150) This invention relates to carburetors and, morespe cifcally, to a novel throttle device for a carburetor which forms acombined means for metering the ow of air and the iiow of fuel.

In the present invention, a fuel metering pin is formed as an Vextensionof the throttle shaft, and the shaft is mounted for translationduring'rotationvrso as to move the pin into and out of an adjustablypositioned orifice. With such a mechanism, given a fuel supply ofconstant head, ow through the orifice can be regulated directly bythrottle rotation.

This invention contemplates a fuel supply which is pressurized so as todeliver fuel to the orifice at substantially a constant head of pressurein 'any position of the carburetor or fuel supply, but the invention isnot limited to such a system using pressure. Instead, the orifice may besupplied from a constant level fuel chamber such as in the customarycarburetor structures having float bowls.

According to this invention, the carburetor has a mix ture conduitproviding a passage of variable area adjacent the fuel nozzle formaintaining a certain range of air velocities in the open positions ofthe throttle. The fuel nozzle is located in the mixture conduit in azone controlled by this variable area means.

According to this invention, the variable area means is so constructedlas to close the fuel nozzle when the engine is not in operation. In thepresent invention, this control means is shown in the form of a springcontrolled poppet valve, but it is obvious to those skilled in the artthat the function of this means may be performed by two separatemechanisms instead of one, and by diaphragm controlled valves instead ofby poppet valves. One form of the present invention is illustrated inthe accompanying drawings, in which:

Fig. 1 is a sectional view through a carburetor showing the throttlevalve in the engine idling position.

Fig. 2 illustrates the same construction with the throttle valve wideopen.

Figs. 1 and 2 in the drawings show a carburetor having a body portion 1containing an inlet 2 to a mixture conduit 3 communicating with an 'airValve seat 4 which divides the mixture conduit intermediate the air horn2 and the throttle body 5. Cast integrally with the body 1 is a boss 7extending into the mixture conduit 3. Boss 7 is bored centrally toprovide a guide for valve stem 8. The valve 9 on stem 8 rests on theseat 4 and controls the passage between the air horn and the throttlebody. Valve 9 is fixed to the stem 8, the latter of which has anextension 10 received within a guide in boss 11 formed integrally withcap 12 which is suitably secured in one side ofthe mixture conduit. Acalibrated spring 13 urges the valve 9 towards its seat 4.

Throttle body 5 is suitably aperturedat `15 to provide a journal bearingfor one end of throttle shaft 16. vThe opposite side of throttle body 5is threaded at 17 for engaging corresponding threads on the opposite endof the throttle shaft 16. Integral with the shaft 16 is a metering pin18, which projects into a metering orifice 19 threadedly engaging a bore20 in the body 1. An exten sion in the form of a stem 21 is formed onthe metering orifice 19 provided with a handle 22 forA adjusting therelationship between the metering orifice 19 and the metering pin 18.The stem 21 is provided with a packing gland 23 to prevent leakagearound the stern.

The body 1 of the carburetor is also provided with a threaded inlet 25for connection with a source of fuel under pressure. The inlet 25communicates directly with the orifice 19 which, in turn, is providedwith Huid passages 26 communicating directly with a fuel nozzle 27 whichleads to valve seat 4. The fuel entering at the supply connection 25 ismetered by the pin 18 before entering the orice which connects directlywith the fuel nozzle.

On the throttle shaft 16 is a throttle valve 30 recessed at 31 toprovide for lateral movement of the throttle shaft 16 by the thread 17,and the range of opening movement of this valve is controlled by a fixedstop 31 when the throttle is wide open, and an adjustable stop 32 forthe idling position. A lever 33 is fixed to the throttle shaft 16 and`carries the stops 31 and 32. Lever 33 is biased to its closed or idlingposition by a torsion spring 34 engaging the lever 33 and a fixed stopon the throttle body 5.

The air horn 2 rotatably mounts a shaft 35 carrying the choke valve 36,which may be manually or automatically controlled, as desired.

Operation The idling speed of the engine can be controlled by adjustmentof the stop 32, which has a tapered end engaging the throttle body 5. Asthe screw 32 moves toward the throttle body, its tapered end will alterthe minimum closed position of the throttle valve 30. The position ofthe throttle valve 30 determines the fuel mixture by varying theclearance between the tapered meter ing pin 18 in the metering orifice19. Adjustment of the handle 22 will therefore determine the amount offuel supply to the fuel nozzle 27 to form the proper mixture. Once thisvsetting has been achieved, then the amount of lead provided in thethread 17, together with the proper configuration for the metering pin18 will determine the amount of opening inthe metering orifice for eachopen position of the throttle valve 30.

As the throttle is opened, threads 17 will move the throttle shaft 16 tothe right, and the throttle valve 30 is recessed lat 31 to permit thismovement. Wide open position of the throttle is limited by the contactof the stop 31 with the throttle body 5.

In Fig. l, the valve 9 is shown seated, which will be generally the casewhen the engine is not in operation. In this position the valve 9 sealsthe fuel nozzle 27 so as to prevent leakage of fuel from the nozzle 27when the engine is not in operation. Such a feature is desirable toprevent continued ow of fuel under such circumstances, regardless ofcarburetor position or the presence of fuel under pressure connected tothe supply connection `25. When the engine is idling, valve 9 will bespaced slightly from the seat 4 either intermittently or continuously,which will allow fuel to escape from the fuel nozzle 27 into an airstream of relatively high velocity. This will be beneficial inthoroughly mixing the fuel and air, and help to maintain some of thefuel, at least, in suspension as it passes through the recess 31 of thethrottle valve 30.

In Fig. 2, the throttle valve 30 is shown wide open and the valve 9 infa position to pass suf`n`cient air for the high speed operation of theengine. In this position of the valve 9, the nozzle 27 is subjected tohigh velocity 3 irow `around 'the valve 9 to aid in atomization of thefuel.

It is possible that the valve 9 can assume different positions for anyposition of the throttle 30, depending, of course, upon the enginedemand for -fuel mixture. It Vis, therfore,- a Vfuel Acontrolacting tomodulate the nete'ring function ofthe pin 18 inthe orifice 19.

`Itis contemplated that thisstructure may bemdied by `those `skilled inthe art in many; ways -without departing from the scope lof -theinvention as defined by the appended claims.

I claim:

`l. In `a carburetoigthe combination of an air horn including an 'airinlet passage, a throttle body for -said carburetor having 'a 4mixtureconduit in offset parallel relation to said air horn passage, asliot'passage exte11din'g at an angle and connecting said air-'hornpassage and said mixture conduit, thereby forming -an abrupt turn in theairflow path through said carburetor, a fuel nozzle in said mixtureconduit in the zone of high velocity airow effected by the abrupt turninsaid airflow 4pathya 4source of -fuel `under substantiallyconstant'pressureconnected to said fuel nozzle, a variable fuel meteringrestriction in said connection, and means adapted to close both saidfuel nozzle and said short connecting passage, said means beingresponsive to airow in said mixture conduit for con trolling the fuelpressure downstream of said fuel metering restriction.

2. In a carburetor, the combination of an air horn havingan air inletpassage, a throttle body for said'carburetor having a mixture conduit inoffset parallel relation to said air horn passage, a short passageextending at an angle and connecting said air horn passage and saidmixture conduit, thereby forming an abrupt turn in the airflow path, afuel nozzle located in said mixture conduit in the zone of high velocityairflow effected by the abrupt turn in the airilow path, a source offuel under substantially constant pressure connected to said fuelnozzle, a variable fuel metering restriction in said connection, andmeans responsive to airflow located adjacent said nozzle to confine theairow path to the wall of said mixture conduit to produce a highvelocity at the abrupt turn in the airflow path when open, and to shutoff the flow of fuel from said nozzle when closed.

References Cited in the file of this patent UNrTED STATES PATENTS635,166 Hay Oct. 17, 1899 976,237 Westmacott Nov. 22, 1910 1,181,356Thompson etal May 2, 1916 1,718,735 Eiker June 25, v1929 2,167,892 Kentet al. i Aug. l, 1939 2,552,465 Spranger May 8, 1951 2,562,826 SharpJuly 31, 1951

